Snap acting device



Sept. 5, 1950 F. B. AUBERT SNAP ACTING uEvIcE 2 Sheets-Sheet 1 Filed Hay17, 1946 INVENTOR.

5L/u@ M BY M ATTORNEY Sept. 5, 1950 F. B. AUBERT SNAP ACTING DEVICE 2Sheets-Sheet 2 Filed May 17, 1946 FIGA .lll 1|] IN V EN TOR.

Maw/KM A, AT TORNEY\ Patented Sept. 5, 1950 UNITED STATES PATENT oFElcE2,521,211 sNAPAoTmG nEvIoE Fred n. Aubert, Detroit, Mich. ApplicationMay 17, 194e, serial No. 670,419

4 claims. (ci. zoo-c1) This invention relates to new and usefulimprovements in snap-acting devices wherein a control means such as avalve or switch is quickly moved to or from a desired position.

An object of the invention is to provide a structure in which thecontrol means is .positively movable by a direct thrust therebyobviating sticking of the control means against movement.

Another object is to provide means to impart a shock or blow to thecontrol means to dislodge it from a stuck position.

Another object is to provide a'switch structure in which the contactmembers have a rolling action upon engagement thereby reducing thetendency of the contact members to fuse together.

The invention consists in the new and improved construction andcombination of parts to be more fully described hereinafter and thenovelty of which will be particularly Ipointed out and distinctlyclaimed.

In the accompanying drawings to be taken as a part of thisspecification, there are fully and clearly illustrated several preferredembodiments oi the invention in which drawings:

Figure 1 is a view in side elevation of a snap acting switch mechanismhaving the casing cover member in section to show the switch structureembodying the invention,

Fig. 2 is a plan view in section on the line 2-2 of Fig. l,

Fig. 3 is a view similar to Fig. 1; but showing the switch mechanism inan operating position.

Fig. 4 is an enlarged detail view showing the various stages of switchstructure movement during the operation of the switch mechanism.

Fig. 5 is a detail view in section on the line 5--5 of Fig. 3,

2 mounting platform. Clamped to the top face of the platform l there isa furcated substantially rectangular resilient arm -5 .of sheet metalwhich extends longitudinally of the base member and carries at its freeend a control means or switch contact member 6. Also secured to thesupporting platform I between the side arms of the ence in a directionaway from the base member.

Fig. 6 is a view in side elevation of a snapacting valve mechanism alsoembodying the invention, f

Fig. 7 is a view in side elevation of another form of switch structureand showing the parts in an intermediate position, and

Fig. 8 is a diagrammatic view of another form of snap switch mechanism.

'Referring to the drawings and particularly Figs. l to 5, i designates abase member of electric insulating material preferably of elongatedrectangular form having a peripheral seat or shoulder 2 to receive ahollow cover member 3 also of electric insulating material. The basemember i is provided with an elevated supporting portion d adjacent oneof its ends and which entends across the base member to provide a Thearms 5 and I are lpreferably formed as by stamping from a single sheetof metal so that they are joined at their end portions which are clampedby a plate 8 and screw 9 to the plat- .form 4. The free end portion I0of the arm ti,

to which the contact member d is secured has intermediate the side armsor members, a tongue or projecting portion II directed toward the freeotally connected to or fulcrumed on the arms t n and 1. It will thus beseen that the arms 5 and 1 and the spring I3 provide three movablemembers which are stressed against each other to form an over-centersnap-acting mechanism which functions to quickly move the arm 5 when thepoint of connection between the arm 'I and spring I3 is moved throughthe line connecting the point of pivotal engagement of the spring i3with the arm 5 and the point or line of connection of the arm 5 to thesupporting platform d.,

Cooperable with the contact member 6 there is a xed switch contactmember I 4 which is carried by a metal bracket or plate member i5 whichis supported on a post I6 of electric insulating material which isrigidly secured to the base member I by a hollow rivet I'I whichprojects from the underside of the base member and is internally screwthreaded to receive a terminal or binding post screw Id.

The coverv member 3 is provided with a stop member I9 which extends intothe casing in overlying relation to the spring i@ and for en-a gagementthereby. It will be noted that the stop member or pin Il@ is positionedso that its point of engagement with the spring it is protected by thecurvature of the spring from straight line relation to the surfaceengagement or point of contact between the contact members l and Il. Thesurface portion of the spring Il which is engageable with the stopmember Il is thus protected by the interposed spring portion 2l from anyimpingement thereon oi' particles of the switch contact material whichmight roughen the abutment engaging portion of the spring surface.Roughness of this spring portion surface would impede free slippage ofthe spring Il on the abutment member I9. The cover member is rigidlysecured in position by cross pins 2l. Also carried by the cover memberthere is a switch operating thrust member or pin 22 having a button orhead portion 23 within the switch casing and which rests on the top faceof the arm 1. The pin 22 is guided for longitudinal reciprocatlon in aguide aperture 23a through the cover member 3 and may be operated by anydesired means such as a bimetal heat motor, a relay armature or thelike. cient strength so that it acts by its inherent resilience underthe force of the arm 1 to bow or bend the contact carrying arm lslightly downward in the position of Fig. 1 and such that when the partsare in the position of Fig. 3, the arm 5 will be bowed or bent slightlyupward. This bowing or bending of the arm 5 results in the contactmember 6 engaging the contact member I4 with a-rolling action therebyreducing the tendency of the contact members to fuse and adhere to eachother upon making contact. The

The spring II has sufiiclamping screw 3 is threaded into a metal tube 2lwhich projects from the underside of the base member I and receives aterminal screw or binding post to receive one lead wire, the other' leadwire being connected to the terminal Il.

The operation of the switch oi Figs. 1 to 5 is as follows: When the pin22 is depressed or moved inward into the casing against the force of thespring blade or the arm 1 and the expansive force of the spring I3, thepoint of engagement between the arm 1 and spring I3 will be moveddownward or toward the arm l. As` the point of engagement between thearm 1 and spring I! moves through the center position or crosses 'theplane of the arm 5, the force .of the spring I3 will exert an upwardcomponent on the arm 5 and snap or quickly move the arm l intoengagement with the contact member Il. The engagement of the contactmember 5 with the contact member Il will be as above noted, with a.rolling action of the surface of the member l on the convex surface of`the member Il. Because of the bias of the arm 1 to its position in Fig.1, the arm 5 will be held in its contact making position only so long asthe pin 22: is exerting suilicient force to overcome the force of thearm 1. When the for exerted on and through the pin 22 is release forswitch breaking movement, the spring arm 1 will move fromJ its full lineposition, Fig. 4, and when it crosses the-line of the arm l there willbe a downward component of force exerted by the spring Il so that innormal operation when the arm 1 has moved say to the dash-dot lineposition, the spring I3 will be exerting sumcientforoe to move the arm 5quickly downward to the switch open position as indicated vby the dottedline of the arm 5 and contact member 5 in Fig. 4. In this dash-dotposition of the arm 1, the spring Il is also in the dash-dot positionand has just come into engagement with the stop member I O. Accordinglyany further upward movement of the l 4 srm'lwmcwetnuprmg utocamurplvoton the stop member Il so that there is a-direct thrust of the spring Ilagainst the arm l. I'his direct thrust by the spring Il against the arml is sufficient to breaky the contact member l away from the contactmember Il in the event that these contact members might have fused andstuck together. In addition to the direct thrust exerted by the springII, the force exerted by the inherent resilience of the arm 1 and theupward component of the end of the spring Il engaging the arm 1, causethe spring Il to strike against the abutment member with a sharp hammerblow which by its reaction through the spring I3 further serves to breakapart the contact members C and I I ii they tend to stick together.

Referring to Fig. 6, 3i designates a valve casing having a valve portorpassageway )I controlled by a valve member l2 which is carried by anoperation arm 33. A stop member Il is preferably provided to limitopening of the valve member and travel of ythe arm Il which is pivotedat 35. Cooperable with the arm 32 there is an expansion spring Il whichis laterally supported for longitudinal expansion and compression withina capsule or tubular member 31 having a reciprocal end portion 3l guidedin the tubular portion and holding the spring It under compression. Thespring supporting member l1 has its opposite ends terminating in conicaltips which are received respectively in an arm or abutment member 3Srigid with the arm 33 and a flange or abutment member 40 rigid with alever arm II pivoted at I2. The three members 3l, I1 and Il aretherefore held under tension against each other by the force of thespring' 35. The point of pivotal engagement 45 of the expansible memberl1 with the abutment member Il is positioned overcenter with respect tothe line connecting the point M of pivotal engagement between the member31 and abutment member ll and the pivot I5 for the arm Il. Accordinglythe spring l5 is exerting aeomponent of its force to urge the valvemember 32 against its seat and closing the port ll. The lever arm II isurged to the position of Fig. 6 by a spring l5 and is limited4 Y wardand overcenter. As soon as the point moves overcenter, lthe spring 3lwill exert a component of its force in an upward direction on the armand snap or quickly move the valve member I2 to open position againstits stop member 5l. Upon movement of point Il overcenter, the member 31will laterally engage thevstop or abutment member Il with a hammer blowto dislodge the valve member vand will thereupon rock or pivot on themember Il so that the member 31 under the force of the heat motor I1will exert a positive direct thrust against the lever arm )lso that the,valve member I2 will be positively moved toward open position andprevented from sticking in closed po sition. The return movement of thevalve member I2 to closed position under the force of the spring ll whenthe heat motor is deenergised and cools, will occur when the point Ilmoves through the line connecting the point 44 and the pivot point 42.

Referring to Fig. 7, there is a, casing 50 having a xed switch contactmember I with which a moving( contact member 52 cooperates, A lever arm53 carries the contact member 52 and is pivotally supported 'on afulcruminember or pin 54.'l Extending longitudinally of the arm 53 thereis an operating arm 55 of resilient material which is bent or bowed asat 56 so that it tends to expand longitudinally. The arm 55 is alsopivoted on the pin 54 and extends longitudinally of the arm 53 with itsfree end portion 51 terminating in spaced relation to an abutmentportion 58 on the arm 53. Pivotally engaging the end portions 51 and 58and held under compression therebetween there is an overcenter member 59which upon overcenterV movement for switch opening movement engages astop member 60 carried by the casing 50. The overcenter member 59 isurged downward or to switch closing position :by a coil spring 6|mounted and guided in the casing 50. Also cooperable with the member 59there is an operating pin or thrust member 62 which is operable oninward movement to overcome the spring 6i and rotate the member 59 abouttheabutment vmember 60 so as to exert a positive direct thrust againstthe lever arm 53. The mem-bers 53, 55, 59 are held under tension againsteach other by the spring portion 56. In the position of the parts inFig. '1, the thrust members 62 has moved the arm 59 upward from theposition in which it is normally held by the spring 6l, the position ofthe parts being an intermediate one such as would occur with sticking ofthe contact members 5i and 52 together with suilicient force so that thedownward component of force of the spring portion 56 could not breakthem apart. Any further upward movement or inward 'movement of themember 52 into the casing will rock the member 59 upon the stop member60 and force the member 52 away from its contact member 5i.

Referring to Figure 8, the switch structure is generally similar to thatof Fig. 1, but-has the U-shaped or bowed leaf spring 10 inverted and hasthe contact carrying end portion 1l of the leaf spring or arm 12 bent orinclined to the main portion of the arm, so that its contact member 13will engage the fixed contact member 1t with a sliding or wiping action.The spring 1t is held under compression between the arm 12 and theoperating arm or leaf spring 15 which is biased in an upward directionor toward the contact member 14 so that it normally tends to l positionthe spring 1l) to urge the arm 12 out of contact making position or awayfrom the contact member 14. Straddling the leaf spring 19, there is anoperating means 16 which is a U-shaped lever pivoted oli center, at 11,so that the leg 18 normally rests by gravity on the arm 15. The otherleg 19 is engageable with the contact carrying lever 12 and the relationof the parts 15, 16 and 12 is such that when the contact members 13, 14are in engagement, the legs 18 and 19 have simultaneous engagement withthe arms and 12 respectively, but only subsequent to movement of the arm15 through center position on its contact separating movement.Therefore, if the contact members 13 and 14 tend to fuse or sticktogether, the force of the -arm 15 is transmitted through the lever 16and directly upon the lever 1,2 to move positively the contact member 13away from the contact mem-` ber 14. Cooperable with the arm 15, there isan operating pin or plunger 80, guided in the casing 8l and operable todepress the arm 15 against its inherent resilience or bias. The pin isoperable to move the arm 15 over or through center so that the arm 15 ispositioned on the opposite side of arm 12 from that shown in Fig. 8 andtherefore moves the spring 10 over-center so that its reaction componentacts upward on the arm 12 and snaps or quickly moves the contact member13 into wiping or sliding engagement with the contact member 14. It maybe noted that upon release of the pin 80, the spring 15 strikes thelever 16 and thus imparts a hammer blow to the arm 12 which in additionto the direct force exerted on the arm 12 through the lever 16 by thearm 15, assures the sudden breaking of contact between the contact mem-Ybers 13 and 14.

It will be apparent from the foregoing that there is provided aconstruction in which the movable control member has a direct thrustimparted thereto to eliminate sticking. By varying the position of theovercenter stop member or the length of the arms of lever 16, the thrustmay be caused to occur either simultaneously with initial overcentermovement or subsequent to such initial movement in order to obtain theadvantage of a hammer blow or shock imparted to the control member. Itshould be further noted, however, that the most desirable use of theprinciple of this invention is as a safety means and that as such thelever action and shock effect would not take place except when there isa failure of the contact members to separate upon normal overcenteraction. The fact that the aforementioned use is deemed the mostdesirable one would not prevent other applications of the principlesince by -proper proportioning of parts said lever action could be madeto take effect in nany position of movement.

Having thus described the invention, what is claimed and is desired tobe secured by Letters Patent of the United States is:

1. In a snap-acting mechanism, a pair of members. one of said membersbeing resilient and of U-shaped form with one leg having pivotalengagement with the other of said pair of members, a third memberextending substantially parallel to said other member and having pivotalengagement withthe other leg of said one member, means supporting saidthird member and said other member for transverse movement of their onemember engaging portions, an abutment member in the path of movement ofthe base portion of said one member, said other member being biasedtoward said abutment means and operable to move said one memberthereagainst with an impact force thereby to transmit the pivotaleii'ect of said impact to said third member, and a control membermovable by said third member.

2. A snap-acting switch, comprising a base member, a supporting memberspaced from and mounted on said base member, a contact member carried bysaid supporting member and facing said base member, a resilient armhaving one end portion positioned between said supporting member andsaid base member and having its other end portion secured to said basemember. a contact member carried by said arm and engageable with saidilrst-named contact member, a resilient operating arm secured at one endportion to said base member adjacent said other end portion of saidfirst-named arm and having its other end portion biased to move awayfrom said base member and being movable from one side to the other ofsaid first-named arm, a leaf spring bowed concavely toward said 'basemember and having its end portions positioned between and tensionedagainst said arms and having its point of engagement with said operatingarm movable through center, a stop member rigid with said base memberand positioned for engagement by the convex surface oi' said leaf springupon movement of said operating arm to the contact member side of saidnrst-named arm, said leaf spring having a portion of its surfaceinterposed in the straightline path between the contact engaging surfaceof said first-named contact member and the portion of said leaf springengaged by said stopmember so that particles of contact member materialwill be prevented from impinging the stop member engaged portion of saidleaf spring, and a plunger cngageable with and operable to move saidoperating arm.

3. In a snap-acting mechanism. a resilient arm xed at one end, a controlmember carried by the other end of said arm, a resilient operating armxed at one end adiacent said one end of said first-named arm and biasedto move in one direction, said arms each having an abutment portionfacing each other, a leaf spring bowed to U-shaped form and having itsend portions engaging said abutment portions, a stop member positionedin the path of movement of and engageable by the external surface of thebase portion of said spring, said operating arm acting to ulcrum saidspring on said st'op member to urge said irst-named arm in a directionopposite to said onedirection, means to move said operating arm againstits bias and the point of engagement of said operating arm and said leafspring gagement with the 6 through center position, and said operatimbeing operable upon release from said overeen movement to move said leafspring stopmsmberwithanimpacttotransmitto first-named arm a shock force.

4. lnasnap-actingmechanismapairofmem-.oneofsaidmembersbeingresilientandof U-shaped form with one leg havingpivotal enother o! said pair of members. a third member extendingsubstantially parallel to said other munber and having pivotal enforcedirectly from said other member to said third member to supplement thereaction force of said one member.

FRED B. AUBERT.

BH'EBENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS Certificate of Correction Patent No. 2,521,277September 5, 1950 FRED B. AUBERT It is hereby certified that errorappears iii the printed specification of the above numbered patentrequiring correction es follows:

Column 8, line 12, strikeout the Words of seid pair of members andinsert -\instead Zeg of said one member;

and that the said Letters Patent should be read es corrected above, sothat the same may conform to the record of the oase in the PatentOffice.

Slgned and sealed this 28th day of November, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommz'sszoner of Patents.

Certificate of Correction Patent No. 2,521,277 September 5, 1950 FRED B.AUBERT It is hereby certified that error appears in the printedspecification of the above numbered patent requiring eorreetien asfollows:

Column 8, line 12, strikeout the Words of said pair of members" andinsert \\instread Zeg of said one member;

and that` the said Letters Patent should be read as corrected above, sothat the same may conform to Jche record of the case in the PatentOliiee.

Signed and sealed this 28th day of November, A. D. 1950.

[SML] THOMAS F. MURPHY,

Assistant 'ommzssioner of Patents.

